Não informado. (1993). Technical Education & Training Abstracts. Carfax Publishing.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Technical Education & Training Abstracts. Oxfordshire, Inglaterra: Carfax Publishing, 1993.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Technical Education & Training Abstracts. Carfax Publishing, 1993.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.